What Is Pheochromocytoma?
Pheochromocytoma (PCC) is a rare tumor of adrenal gland tissue. The adrenal glands are located above the kidneys. The adrenals produce a number of hormones, including aldosterone, testosterone, cortisol, norepinephrine, and epinephrine. These hormones regulate vital bodily functions such as blood pressure, stress, blood sugar, immune response, metabolism, and heart rate. If your body produces more or less of any of these hormones than it needs, you can become ill. Growths on the adrenal glands can affect hormone production. In the case of PCC, the tumors cause your adrenal glands to make too much norepinephrine and epinephrine. Pheochromocytoma is rarely cancerous, but it can be dangerous due to fluctuating hormone levels.
Eighty five percent of PCCs are in the adrenal glands themselves. The other 15 percent are outside of the adrenals (Garg et al. 2011). Tumors outside the adrenals are called paragangliomas. PCCs make and release the catecholamines (adrenal hormones) epinephrine, norepinephrine, and dopamine. These specific hormones control heart rate, metabolism, and blood pressure.
Symptoms are caused by the increased hormone levels. Stress may induce an adrenergic crisis (AC). AC results from a sudden increase in adrenal hormones. The increase in hormone production can cause a wide range of problems that can be potentially fatal if not treated. Hyptertension, or high blood pressure, is an example of a complication that can stem from adregeneric crisis. High blood pressure increases your risk of heart disease and stroke.
Diagnosis of pheochromocytoma relies on irregularities in hormone levels. High levels of catecholamines can be indicative of the tumors.
Outlook depends on two conditions: correct diagnosis and an expert surgeon. Successful surgeries are hopefully followed by recovery. Normal life expectancy is typical after full recovery.
Risk Factors for PCC
PCC is believed to be linked to conditions in which hypoxia (reduced oxygen supply) happens.
- severe hypertension (high blood pressure)
- congenital heart disease
PCC can develop at any age, but is most common from early to mid-adulthood.
Causes of PCC
PCC was once believed to occur randomly. Recent research indicates that it may be inherited. That means it is passed down through families (Mayo Clinic).
Patients who inherit pheochromocytoma from their parents may also suffer from associated genetic conditions. These conditions include:
- Von Hippel-Lindau disease (VHL) – a condition in which cysts and tumors grow in the central nervous system, on the brain, kidneys, adrenal glands, or other areas of the body
- Neurofibromatosis 1 (NF1) – the development of tumors on the skin and optic nerve
- Multiple endocrine neoplasia type II (MEN) – a form of thyroid cancer that develops in conjunction with PCC
PCC may be associated with congenital heart disease. Heart disease can cause hypoxia which contributes to PCC.
Symptoms of PCC
Symptoms result from excess hormone production and release. A sudden large increase in adrenal hormones is called an adrenergic crisis (AC). AC causes severe hypertension (high blood pressure) and tachycardia (fast heart rate).
Classic symptoms of PCC are:
- episodic and sudden onset of severe headaches
- abdominal pain
- hypertension (high blood pressure) which may be resistant to conventional medications
- rapid heart rate
- irritability and anxiety
Common causes of adrenergic crisis are:
- drugs (corticosteroids, chemotherapy agents, etc.)
- surgical anesthesia
- emotional stress (may cause adrenals to produce excess hormone)
Diagnosis of PCC
Diagnosis of PCC has improved with modern technology. However, PCC is still difficult to diagnose. If you have symptoms, your doctor will order tests. These include
imaging tests to look for tumors:
- magnetic resonance imaging (MRI)
- positron emission tomography (PET) imaging
- laboratory tests to assess hormone levels:
- blood plasma (testing for catecholamine and metanephrine levels)
- urine test (testing for catecholamine and metanephrine levels that may have been missed in the blood test)
Treatment of PCC
The best treatment for PCC is surgery. The surgery is a delicate procedure. Without ample preparation of the patient, it can be life threatening.
Doctors prepare the patient by:
- discussing all existing medications because some can interfere with PCC during surgery.
- letting the anesthesiologist know of all medications prior to surgery.
Post-surgery patients may have short-term problems with adrenal hormone regulation. Steroids can substitute until the adrenals restart normal function.
Complications of PCC
Surgery for PCC can have many complications. The surgery affects powerful hormones in the body. During an operation, some of the problems that may develop are
- hypertension (high blood pressure)
- hypotension (low blood pressure)
- arrhythmias (abnormal heart rhythms)
In rare cases, PCC may be cancerous. Complete surgical removal of a malignant PCC is encouraged. Surgery is followed with radiation therapy or chemotherapy.
What Is the Long-Term Outlook?
Undiagnosed PCC is potentially fatal. Without treatment, those with PCC are at a high risk for death. Reasons for death include
- hypertensive crisis (high blood pressure crisis)
- arrhythmia (irregular heart beat)
- myocardial infarction (heart attack)
- multisystem crisis (multiple organs of the body begin to fail)
Early diagnosis is not enough to ensure successful treatment. The surgeon must be highly skilled and able to handle the likely complications of surgery.
With both well-timed diagnosis and a practiced surgeon, the surgical death rate is between two and three percent (Garg et al. 2011). Most patients may look forward to a normal life expectancy after surgery.